Easy Tuck (tm) 300 Thread Count 100% Combed Cotton Sheet Set (Slate, King) Combed Cotton 300 thread count mercerized 100% combed cotton. Making your bed has never been easier. Patented original design. Great for people with back pain, restless sleepers or if you just want a simple way to achieve a neat, tailored bed. Deep pocket design fits up to 19" pillowtop mattresses.